void sleep_mode_init();



int main(void)


{

	sleep_mode_init();		
	_SEI;
	set_sleep_mode(SLEEP_MODE_PWR_DOWN);		 
        sleep_mode();
								 
         while(!(PIND & (1 << PIND3)))					//Warte bis Taste losgelassen
   	{
	;
	}


        start:

	if(b >= 450000)							//450000 entsprechen den 4 Sekunden
	{
	b = 0;
	 

	sleep_mode_init();		
	_SEI;
	set_sleep_mode(SLEEP_MODE_PWR_DOWN);		 
        sleep_mode();	
							 
        while(!(PIND & (1 << PIND3)))					//Warte bis Taste losgelassen
	{
	;
	}

        }

        while(1)
        {
        	if(!(PIND & (1 << PIND3)))
		{
		while(!(PIND & (1 << PIND3)))  					 
		{
		b++;

		if(b >= 451000)
		b = 450500;

		if(b == 450500)
		{
		PORTB = 0x00;
		PORTD = 0x00;
		PORTC = 0x00;
		}
		}

	goto start;
	}
       }
}


void sleep_mode_init()
{
     	
	SMCR &= ~(1 << SM0) | (1 << SM2);  				//Power Down Modus
	SMCR |=  (1 << SM1) | (1 << SE);				//Power Down & Sleep Enable

	EICRA &= ~(1 << ISC11) | (1 << ISC10);   			//Low Level of INT1 generates Interrupt Request
	EIMSK |= (1 << INT1);						//External Interrupt Request Enable
	PORTB &= ~(1 << PB4);
}



ISR(INT1_vect )
{
	while(!(PIND & (1 << PIND3)))
	{
	;
	}
	EIMSK &= ~(1 << INT1);						//External Interrupt Request disable
}